The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Modern combustion engines are often equipped with microprocessor-based controller and sensors to monitor and beneficially alter operational parameters over time. Exemplary of such systems in general are those which control parameters that affect fuel combustion, including ignition timing, fuel injection mass and timing, exhaust gas recirculation, and engine cooling, among others.
In general terms, for a given engine r.p.m. or range of engine r.p.m's, a particular combination or range of values or settings for the many parameters under control provides the most desirable operation of an engine, as pre-determined by an engineer or other person on a basis that may include fuel economy, emissions, power output, or any other selected criteria. Once criteria are established, an engine may be commanded to operate to provide a desired operation. However, owing to changes in engine system components over time, or other factors, an engine may experience undesirable performance including undesirable combustion results (e.g. misfires or partial burns).